Separators, particularly magnetic separators, are now widely fitted to domestic and commercial central heating systems. The separators remove debris, and particularly magnetic debris, from the heating fluid. This keeps the heating fluid clean, preventing build-up of debris in, for example, the boiler, where it may cause expensive damage.
When a heating system is serviced, the magnetic separator must be cleaned to remove the particles which have been separated from the fluid. A removable screw-top is typically provided at the upper end of a cylindrical housing which, when removed, allows access to the inside of the cylindrical housing. A removable insert is typically provided within the housing, which can then be removed for cleaning. Although it is preferable to install the filter with enough space to allow the insert to be removed, this is not possible in every installation. It is therefore useful to provide a connection which allows the whole filter to be easily removed from the heating circuit.
The insert may also include a separate chamber, typically smaller than the main chamber, through which a portion of circulating flow may pass. The flow in the smaller chamber is generally slowed by obstacles, causing non-magnetic particulate matter to fall out of the flow. The benefit of having the separate chamber is that the flow in the main chamber is substantially unrestricted and pressure drop across the separator is minimized.
It is understood that where a magnet is used to separate magnetic debris, to be most effective, any plastics sleeve over the magnet needs to be of thin material to maximize the effect of the magnet in the chamber. Manufacturing a thin sleeve poses significant design and manufacturing problems, particularly where the magnets to be covered are greater than a certain length, for larger separators used in larger heating systems.
Generally isolation valves are used to connect a separator to a central heating circuit and these valves are connected to the inlet and outlet by either push fit or screw connections. On small separators, designed for systems with typically up to 22 mm pipework running to and from the boiler, push fit connectors are preferred and the applicant has developed designs for connecting and disconnecting both the inlet and outlet connections simultaneously, which are disclosed in for example PCT/GB2013/052880. This is of significant benefit, because it is extremely difficult, if not impossible, to release more than one push fit connector at a time. However, problems arise in trying to design similar arrangements for larger separators, for example, for fitting to 28 mm pipe work. Push-fit connectors are generally less reliable for larger pipe sizes, and the larger spacing between the inlet and outlet makes it difficult to produce a release tool to release both connectors simultaneously.
Where 28 mm connections to separators are currently made, the connections are exclusively screw connections and require large spanners or tools to tighten and release. Use of tools of this size can be difficult where space is limited. Also, the inlet and outlet ports on separators are typically made from plastics, and large torsional forces from a spanner on the ports to disconnect and reconnect from the fittings and/or pipe may cause weakness or cracks in the separator housing over time, resulting in leakage. If a separator housing becomes cracked, then it is unlikely that an effective repair will be possible, and the separator will have to be replaced. Once any threaded connection has been undone, it may still be difficult to remove a separator from its fittings, particularly if it has not been removed for a long time, because the seals may have hardened and stuck to the parts.
It is also easy to damage a plastic thread by over-tightening and cross-threading. If damage does occur, it is nearly impossible to repair.
It is an object of this invention to provide a connection assembly for a separator which reduces or substantially obviates the above mentioned problems.